Permanent P0420

bbermann

Last month I got a PO430. Its for the other bank. I was running Berk HFCs I had bought used so I just bought a new set and that cleared it.

Never had a problem with the Berks and codes before that...either before or after tuning.

Wilson2608

I think berk does a good job at keeping the code off, I actually had berk HFC when I bought my car without knowing. Had the code come pop up one time and I cleared it and it never returned. When I went to buy HFC( because I never knew I had them on my car in the first place) I replaced them with Z1 brand and it threw a code within 15 minutes and would not go away without a tune. I later found out I had berks on my car when trying to sell what I thought was a stock cat lol

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Stillen G3, z1 Intake Manifold, Stillen Headers, Z1 HFC's, Stillen Catback. 330whp 267 ft- lbs tuned at Z1 motorsports.

Alexwallace23

I really do not want to spend the money on new HFCs to troubleshoot this problem. I think this may be an O2 sensor issue. I say this because the permanent P0420 went away after a day. Codes P0430 and P0420 came up last weekend. So supposedly both HFCs are operating below the threshold, but once again, the codes went away after a day.

I assume if the HFCs were going bad the codes would always be there.